NAME

SYNOPSIS

DESCRIPTION

setresuid sets the real user ID, the effective user ID, and the saved
set-user-ID of the current process.
Unprivileged user processes (i.e., processes with each of real,
effective and saved user ID nonzero) may change the real, effective and
saved user ID, each to one of: the current uid, the current effective
uid or the current saved uid.
The super-user may set real, effective and saved user ID to arbitrary
values.
If one of the parameters equals -1, the corresponding value is not
changed.
Completely analogously, setresgid sets the real, effective and saved
group ID's of the current process, with the same restrictions for
processes with each of real, effective and saved user ID nonzero.

RETURNVALUE

On success, zero is returned. On error, -1 is returned, and errno is
set appropriately.

ERRORS

EPERM The current process was not privileged and tried to change the
IDs is a not allowed way.

CONFORMINGTO

This call is nonstandard.

HISTORY

This system call was first introduced in HP-UX. It is available under
Linux since Linux 2.1.44. These days it is also found in FreeBSD (for
emulation of Linux binaries).

NOTES

Under HP-UX and FreeBSD the prototype is found in <unistd.h>. Under
Linux there is so far no include file giving the prototype - this is a
glibc bug. Programs using this system call must add the prototype
themselves.